1. Field of the Invention
This invention relates to a safety mechanism, for use in the detonation of explosives.
2. Description of Related Art
The main charge in an explosive weapon, e.g. a mine, is normally detonated by a small explosive pellet (with one or more intermediate explosive stages). The pellet is stored in a safe position in which it cannot be activated and, when the weapon is armed, is moved into an active position where it is in line with an intermediate explosive which in turn is contiguous with the main charge. In the active position, mechanical energy, e.g. a spring loaded hammer, or electrical energy, e.g. a current pulse through an inbuilt resistor, is injected into the initiating pellet when the weapon is required to be fired. In the case of the mechanical hammer the pellet must of course be under the hammer in the active position in order to be struck, and in the case of the electrical impulse the resistance wire is only in circuit when the pellet is in the active position.
All movement of the mine is carried out with the pellet locked in the safe stored position and only when the weapon is to be armed is the pellet moved to the active position. A single event, electrical or mechanical stimulus, is then required to explode the weapon.
However, unsafe conditions can arise from many causes, particularly when, after arming, the mechanical or electrical stimulus fails to trigger the explosion. The pellet is then in the active position and it is not known whether the stimulus will arise unexpectedly at any moment.